WinRAR is a 32-bit Windows version of RAR Archiver, an archiver and archive manager. RAR files can usually compress content by 8 percent to 15 percent more than ZIP files can.
Link: http://www.download.com/WinRAR/3000-2250_4-10007677.html?tag=contentBody;mostPopTwoColWrap&cdlPid=10890490
Knowledgebase : Downloads > Utilities